Mobile communication systems were developed to provide mobile users with communication services. With the rapid advance of technologies, the mobile communication systems have evolved to the level capable of providing high speed data communication service beyond the early voice-oriented services.
Recently, standardization for a Long Term Evolution (LTE) system, as one of the next-generation mobile communication systems, is underway in the 3rd Generation Partnership Project (3GPP). LTE is a technology designed to provide high speed packet-based communication of up to 100 Mbps and aims at commercial deployment around 2010 timeframe. In order to accomplish the aim, a discussion is being held on several schemes, e.g. reducing the number of nodes located in a communication path by simplifying a configuration of the network and maximally approximating wireless protocols to wireless channels.
Meanwhile, unlike voice service, the data service is provided on the resource determined according to the data amount to be transmitted and channel condition. Accordingly, the wireless communication system, especially cellular communication, is provided with a scheduler which manages transmission resource allocation in consideration of the required resource amount, channel condition, data amount, etc. This is the fact in the LTE system as the next generation mobile communication system, and the scheduler located at the base station manages the transmission resource allocation.
Recent studies are focused on the LTE-Advanced (LTE-A) for improving data rate with the adoption of various new techniques to legacy LTE system. Interference Mitigation and Traffic Adaptation (IMTA) is one of the techniques being studied for use in the LTE-A system. The IMTA is a technique of changing the ratio between uplink and downlink resource allocation amounts at a short cycle for controlling the uplink and downlink traffics and interference amounts in TDD mode. In order to implement the IMTA technique efficiently, it is necessary to improve the LTE-A system in various respects.